Lost Red Zebra

I could not find m red zebra he was the largest I my tank, the boss, and loved to dig. After not seeing when I got home the next day I moved the rocks to find he was under. He had sand in mouth and gills, could he have choked himself?

I was thinking also maybe the rock shifted and he got trapped anyone ever experience this?

Sorry about your fish. My female kenyi is bad about it. I'll come home and find a rock pile collapsed that I have made for them. She will dig out the supporting gravel under the rocks so it is possible.